clark



I o garish -tstrs gaunt fixer.

STUART GWYNN, OF NEW YORK, N. Y, ASSIGNOR TO SPE NCER CLARK,

' OF WASHINGTON, DISTRICT OF COLUMBIA.

Letters Patent No. 81,495, dated August 25,1868.

IMBROVEMB'NT IN PREPARING 011s.

TO ALLWH OMIT MAY CONCERN:

Be it known that I, STUART GWYNN, of the city, county, and State of NewYork, have invented a new Preparation of Oils, used as vehicles forspreading and attaching pigments to surfaces, and for similar pur-'poses; and I do hereby declare the following to be a full and exactdescription thereof, and of the mode of preparing the same.

The nature of my invention consistsin a new and improved process fortreating linseed and other oils, which is partly chemical and partlymechanical, as hereinafterfully described, whereby I obtain a new andvaluable product, possessing superior advantages foruse in painting andother mechanical purposes.

The forms of apparatus and mechanical appliances which I have found bestadapted to effectuate my process for producing my improved oils arefully describedsin a separate application for Letters Patent which I'shall file herewith, and to which reference may be had for details, andI shallherein only specify the same in general terms. In the use ofoil'of vitriol in my processfll employ an agent which for ,many yearspast has been used in the purification of oils, with a view to carbonizeparticles thereof. In some of the processes, attempts have'boen made tosubsequently remove and neutralize the acid thus employed, by means ofcarbonates of the alkalies and alkalineearths. With petroleum, and withfixed animal and greasy vegetable oils for lubrication and burning,reasonably good products haye thus been obtained, and when petroleumthus -treated is redistilled, an excellent illuminating-oil has beenproduced, but the results have never been satisfactory with oils forpainting. I have, by my process, obtained perfect success in thepreparation of such oils. This process naturally dividcls itself intofive operations,.as follows First, oxidizing: subsidence anddecantation.

Second, neutralizing: subsidence and decantation.

Thirdysteaming subsidence and dccantation.

' Fourth, evaporation of aqueous and other volatile matters foreign tothe oil andinjurious if lcftthercin:

subsidence and decantation.

'Fii't'h, sun-bleaching The first operation, viz, oxidation, is effectedby treating linseed or other oil with sulphuric acid of 66F Baume, inthe proportion of from two and a half to five pounds of acid, by weight,to one hundred gallons of oil, the oil being kept, by suitablemechanical appliances, in a state of constant and violent agitation, andthe acidmeanwhile added thereto very slowly, in exceedingly minutequantities. It is better that the agitation of the oil begin before thefirst dose of acid is put in, and that it be continued withoutintermission for at least two hours after the entire quantity has beenadded. The acid may be added in small quantities everyhalf hour, untilthe properproportion has been used. After subsidence for atleastfifteen'hours, the clear oil remaining is carefully decanted into avessel and heated. I prefer to obtain the necessary heat from asteampipe in the bottom of the vessel, the pipe being covered to adepthof about one inch with water before the oil isintroduced, and the steammay be allowed to escape from the pipe in fine jets, and pass up throughthe oil, to heat the same. So soon as the oil is heated allsc-um risingto the surface is carefully removed.

The second opcrat'ionfviz, neutralization, is now effected by, addingmilk ofcaustic lime to the oil in small quantities, attintcrvals of fromten to fifteen minutes, the oil being keptconstantly heatcd, and theebullition of steamv through the some, if steam be thus used,continually maintained. In the mean time, constant tes'ts'ar'e madewithlitmus-paper or other suitable agents, and so soon as the slightestalkaline reaction is observed, the addition of,the milk of lime isdiscontinued. Any excess of the lime.wculd form a soap, entailing anabsolute loss of a portion of the oil," and injurious to the remainder}It is desirable that the oil be kept heated foritwo or three hours afterits neutralization has thus been eil'ectcd, to allow a completeseparation of foreign matters therefrom, and a deposit thereof bysubsidence with the sulphate of lime. After standing'from ten to fifteenhours, the clear oil is again decanted with care into a third vessel,for the third operation, viz, steaming.

This consists in submitting the oil to thedireot action of steam passingthrough the same for from'four to five hours, which will produce amolecular change in the oil, predisposing it to unite more readily withoxygen, and also causing it to part with aqueous and otherparticlesdetrimental thereto. After subsidence, the oil is drawn oil clear, fromthe watery sediment in the steaming-tank into an open vessel or boiler,in which, as the fourth operetiornit is heated up to a temperature offrom 215 to 400 Fahrenheit, and kept at this point for from three tofive hours, depending upon the use to which the oil is to be applied,and the nuture'of the raw oil used. After being allowed to cool andsubside in the boiler, the clear oil is finally run into shallowbleachingvuts or tanks, to a. depth of from four to twelve inches, andexposed five days or more to the action of light, to render it clear andcolorless.

Having thus fully described my invention, I claim as new, and desire tosecure by Letters Patent- Oils prepared and purified in the manner whichI have herein set forth STUART GWYNN.

Witnesses:

W. Gr. Memos, L. BOUVIER.

